Left ventricular function by echocardiography in children with fixed aortic stenosis.

Left ventricular function was evaluated echocardiographically within 24 hours of cardiac catheterization in 45 children with fixed aortic stenosis. Left ventricular systolic time intervals, mean velocity of circumferential fiber shortening, left ventricular end-diastolic volume and shortening fraction were evaluated. Some patients with severe aortic stenosis had a shortened preejection period, prolonged ejection time and increased mean velocity of circumferential fiber shortening in comparison with normal subjects, but these findings were not consistent within the group with severe aortic stenosis or apparent in patients with mild or moderate aortic stenosis. Left ventricular end-diastolic volume was smaller in children with severe obstruction than in normal children. Evaluation of the shortening fraction provided good separation of patients with significant obstruction from those with mild disease. Further, there was a linear correlation between the shortening fraction and the left ventricular-aortic gradient demonstrated at cardiac catheterization. This correlation was also of use in evaluating the response of patients to surgical relief of obstruction. Pre- and postoperative echocardiographic evaluation of the shortening fraction appears to provide a readily available noninvasive method of assessing the course and severity of obstruction in fixed aortic stenosis in children.